Ballistic impacts on an anatomically correct synthetic skull with a surrogate skin/soft tissue layer

Abstract

The aim of this work was to further develop a synthetic model of ballistic head injury by the addition of skin and soft tissue layers to an anatomically correct polyurethane skull filled with gelatine 10% by mass. Six head models were impacted with 7.62 x 39 mm full metal jacket mild steel core (FMJ MSC) bullets with a mean velocity of 652 m/s. The impact events were filmed with high-speed cameras. The models were imaged pre-and post-impact using computed tomography. The models were assessed post impact by two experienced Home Office pathologists and the images assessed by an experienced military radiologist. The findings were scored against real injuries. The entry wounds, exit wounds and fracture patterns were scored positively, but the synthetic skin and soft tissue layer was felt to be too extendable. Further work is ongoing to address this.

Forensic reconstruction of two military combat related shooting incidents using an anatomically correct synthetic skull with a surrogate skin/soft tissue layer

“…The skin exit wounds scored lower in models 1-4 when compared with the models shot without helmets [10]. The wounds in the models without helmets tended to be larger with a more 'ragged' appearance [10] (Fig.…”

“…One of these is the post-mortem cut line in the skull, discussed in [9,10], which interferes with fracture propagation. Another is the extendable nature of the synthetic skin, discussed in [10]. Work is ongoing to address the skin properties, but we elected to shoot these models with the known skin material to assess if the presence of the helmet altered the skin wounding appearances.…”

“…In order to allow comparison with our previous work [9,10,16], casualties were identified where 7.62-mm bullets were confirmed responsible for the injuries (this included 7.62 × 39, 7.62 × 51 and 7.62 × 54R mm). Seven casualties were confirmed as such.…”

“…Models are described in the text by the helmet number shown in white. The black numerals on the faces indicate that they are sequential to those described in [10] The anonymised CT images and summary of the incidents (engagement range, calculated impact velocity of the bullet and selected IMAP images) were collated as laminated A4 sheets, one set for each shooting, and labelled 'Incident 1' and 'Incident 2'.…”

The use of gelatine in wound ballistics research

“…A number of polymeric bone simulants exist and have been used to represent skulls, e.g. [ 19 , 38 – 40 ], and other bones [ 41 – 43 ]; these may be anatomically accurate or a simple geometric representation.…”